1. Identifying SARS-CoV-2 antiviral compounds by screening for small molecule inhibitors of Nsp14 RNA cap methyltransferase
- Author
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Kang Wei Tan, Emma L. Roberts, Tiffany Mak, Lucy S. Drury, Souradeep Basu, Berta Canal, Michael Howell, Joseph F. Curran, Florian Weissmann, Karim Labib, Tom D Deegan, John F.X. Diffley, Allison W McClure, Ryo Fujisawa, Mary Wu, Victoria H. Cowling, Rachel Ulferts, Clovis Basier, Rupert Beale, Theresa U. Zeisner, and Chew Theng Lim
- Subjects
Methyltransferase ,Indoles ,coronavirus ,Drug Evaluation, Preclinical ,Viral Nonstructural Proteins ,medicine.disease_cause ,Biochemistry ,Substrate Specificity ,Phenothiazines ,Chlorocebus aethiops ,Fluorescence Resonance Energy Transfer ,Coronaviridae ,Viral Regulatory and Accessory Proteins ,Research Articles ,Coronavirus ,0303 health sciences ,Alanine ,Translation (biology) ,Small molecule ,covid-19 ,Indenes ,mRNA cap ,RNA Caps ,Indazoles ,Viral protein ,Biology ,Chlorobenzenes ,Antiviral Agents ,Small Molecule Libraries ,03 medical and health sciences ,Biochemical Techniques & Resources ,Trifluperidol ,Virology ,Nitriles ,medicine ,Animals ,Molecular Biology ,Vero Cells ,030304 developmental biology ,Enzyme Assays ,030306 microbiology ,SARS-CoV-2 ,RNA ,Reproducibility of Results ,Cell Biology ,Methyltransferases ,biology.organism_classification ,Adenosine Monophosphate ,High-Throughput Screening Assays ,Viral replication ,Purines ,Exoribonucleases ,methyltransferase - Abstract
The COVID-19 pandemic has presented itself as one of the most critical public health challenges of the century, with SARS-CoV-2 being the third member of the Coronaviridae family to cause a fatal disease in humans. There is currently only one antiviral compound, remdesivir, that can be used for the treatment of COVID-19. To identify additional potential therapeutics, we investigated the enzymatic proteins encoded in the SARS-CoV-2 genome. In this study, we focussed on the viral RNA cap methyltransferases, which play key roles in enabling viral protein translation and facilitating viral escape from the immune system. We expressed and purified both the guanine-N7 methyltransferase nsp14, and the nsp16 2′-O-methyltransferase with its activating cofactor, nsp10. We performed an in vitro high-throughput screen for inhibitors of nsp14 using a custom compound library of over 5000 pharmaceutical compounds that have previously been characterised in either clinical or basic research. We identified four compounds as potential inhibitors of nsp14, all of which also showed antiviral capacity in a cell-based model of SARS-CoV-2 infection. Three of the four compounds also exhibited synergistic effects on viral replication with remdesivir.
- Published
- 2021